The present invention relates to manufacturing and packaging apparatus.
In particular, the invention concerns mass production and mass packaging apparatus for roll products, especially for tissue paper or absorbent cellulosic rolls used for sanitary or household purposes. The apparatus includes, from upstream to downstream, a cutting station to cut consecutive, very long rolls of a given diameter into sequences, spaced or not, of several shorter rolls, furthermore, an upstream conveyor to move the roll sequences from the cutting station to a feeder station which distributes the rolls, sequence after sequence, to several automated packaging stations.
Many designs of apparatus for manufacturing roll products for sanitary or household uses are already known.
Such apparatus is based on the principle of simultaneously implementing all the roll manufacturing stages in a single fabrication line, from loading very long rolls called xe2x80x9clogsxe2x80x9d to the packaging of the rolls cut into smaller sizes.
There are many kinds of cutting stations. Overall they use band saws or circular saws to ensure regular log cutting and final roll cutting.
Beyond the cutting station, the roll sequences made from the logs are conveyed to one or more packaging stations.
In general, a problem arises when moving the rolls from a cutting station to a packaging station because the known apparatus incur the drawback of being susceptible to roll accumulation, even xe2x80x9cpile-upxe2x80x9d, whereby the manufacturing apparatus may be stopped.
To prevent the as yet unpackaged rolls from accumulating in the conveyance system, a feeder station already has been used at the exit of the cutting station to distribute the as yet unpackaged rolls between several packaging stations.
In general, the feeder stations thusly combined with the conveyance system include a selector to direct the rolls toward several downstream conveyors each leading to a packaging station.
Such a design may be embodied by a feeder station similar to that described in U.S. Pat. No. 4, 440, 289.
The feeder station of this patent is integrated into an upstream conveyor which is a central moving belt above which is mounted a flap rotatable about an axis parallel to the longitudinal direction of the central moving belt and able to drive the rolls to either side of the moving belt in the direction of several downstream conveyors to distribute and balance the permissible load of rolls across the packaging stations.
Such a design, however, incurs several major drawbacks.
The feeder station is able to move only a limited number of rolls simultaneously, the central belt temporarily stopping each roll opposite the flap prior to the roll being discharged, whereby the overall roll conveyance speed in the manufacturing apparatus is lowered. Moreover, the rolls are susceptible to being warped or soiled by their direct contact with the flap and, if so, may represent a significant commercial loss.
To remedy this condition, the present invention provides a feeder station eliminating contact between it and the rolls and, therefore, leaving unimpaired the roll conveyance speed in the manufacturing apparatus.
For that purpose, the invention provides manufacturing apparatus of the above described type which is characterized in that a feeder station roll-switching system allows orientation of each roll sequence toward a specific set of packaging stations, where the orientation is different from that toward which the previous sequence had been directed.
In other features of the invention:
the upstream conveyor is substantially horizontal and independently drives the roll sequences in a given direction at a higher speed than that of the sequences leaving the cutting station in order to separate the sequences at a minimum spacing to ease their switching,
the roll-switching system includes a set of vertical blades which can simultaneously rotate about mutually parallel vertical shafts spaced apart by the width of one roll and able to take up, from one roll sequence to the next, two distinct angular positions relative to the conveyor""s direction of advance for the purpose of orienting the rolls of one sequence toward one set or another of downstream conveyors relating to the oriented angular position, the downstream conveyors moving the rolls toward a set of packaging stations associated with the oriented angular position,
the roll-switching system includes a set of stationary and parallel vertical plates spaced apart by the width of one roll and coplanar intermediary conveyors rotatable about a horizontal axis are perpendicularly configured between the plates and are able to simultaneously assume from one roll sequence to the next two different angular positions to orient the rolls of one sequence toward either of the two downstream sets of conveyors arrayed at two levels, each downstream conveyor set associated with each oriented angular position moving the rolls toward a set of packaging stations associated with the oriented angular position,
the manufacturing apparatus includes a control unit receiving data from components of the apparatus and controlling other components of the apparatus,
the control unit receives a signal denoting the speed of the rolls leaving the cutting station and a transit signal from the roll sequences,
the control unit calculates the distance between two consecutive roll sequences and, thereupon, driven by an internal program, controls the angular position of the blades or of the intermediary conveyors and the speed of the upstream conveyor.